The specific aim of this project is to develop Magnetic Disk Array (MDA) technology for ultra-sensitive and inexpensive molecular analysis for cancer research and diagnosis. The major goals of Phase I are to develop and complete a laboratory MDA device, to introduce a technique for tagging biomolecules by magnetic particles, and to demonstrate rapid and reliable DNA detection with the MDA. The approach we propose is to utilize a new method for preparing and detecting magnetic clusters bonded by a DNA molecule to the surface of a disk which is very similar to a conventional computer diskette. With this approach spacial location of a magnetically tagged DNA can be determined by monitoring magnetic properties of the surface and then can be used to identify the DNA sequence following the same approach as was recently introduced by DNA-on-chip technologies. During Phase I, the specific aims are (1) to systematically investigate magnetic tagging materials to be used for the Magnetic Disk Array (2) To develop the MDA device and evaluate the performance of magnetic disk reading equipment. Special effort will be made to achieve ultra-sensitive DNA detection (3) To demonstrate the use of MDA for monitoring DNA hybridization without the need of amplification of targets DNA. PROPOSED COMMERCIAL APPLICATIONS: The potential commercial applications of MDA include mutation screening for cancer and genetic disease diagnosis for hospitals. Due to fast speed analysis, it is very valuable for biomedical research. It also can be used for DNA fingerprinting for forensic applications as well as rapid microbial DNA analysis in field for biological weapon analysis.